mcs/class/corlib/System/ValueType.cs

   1 //
   2 // System.ValueType.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Gonzalo Paniagua Javier (gonzalo@ximian.com)
   7 //
   8 // (C) Ximian, Inc.  http://www.ximian.com
   9 // (C) 2003 Novell, Inc.  http://www.novell.com
  10 //
  11
  12 //
  13 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System.Reflection;
  36 using System.Runtime.CompilerServices;
  37
  38 namespace System
  39 {
  40         [Serializable]
  41         public abstract class ValueType
  42         {
  43                 protected ValueType ()
  44                 {
  45                 }
  46
  47                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  48                 internal extern static bool InternalEquals (object o1, object o2, out object[] fields);
  49
  50                 // This is also used by RuntimeHelpers
  51                 internal static bool DefaultEquals (object o1, object o2)
  52                 {
  53                         object[] fields;
  54
  55                         if (o2 == null)
  56                                 return false;
  57
  58                         bool res = InternalEquals (o1, o2, out fields);
  59                         if (fields == null)
  60                                 return res;
  61
  62                         for (int i = 0; i < fields.Length; i += 2) {
  63                                 object meVal = fields [i];
  64                                 object youVal = fields [i + 1];
  65                                 if (meVal == null) {
  66                                         if (youVal == null)
  67                                                 continue;
  68
  69                                         return false;
  70                                 }
  71
  72                                 if (!meVal.Equals (youVal))
  73                                         return false;
  74                         }
  75
  76                         return true;
  77                 }
  78
  79                 // <summary>
  80                 //   True if this instance and o represent the same type
  81                 //   and have the same value.
  82                 // </summary>
  83                 public override bool Equals (object o) {
  84                         return DefaultEquals (this, o);
  85                 }
  86
  87                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  88                 internal extern static int InternalGetHashCode (object o, out object[] fields);
  89
  90                 // <summary>
  91                 //   Gets a hashcode for this value type using the
  92                 //   bits in the structure
  93                 // </summary>
  94                 public override int GetHashCode ()
  95                 {
  96                         object[] fields;
  97                         int result = InternalGetHashCode (this, out fields);
  98
  99                         if (fields != null)
 100                                 for (int i = 0; i < fields.Length; ++i)
 101                                         if (fields [i] != null)
 102                                                 result ^= fields [i].GetHashCode ();
 103
 104                         return result;
 105                 }
 106
 107                 // <summary>
 108                 //   Stringified representation of this ValueType.
 109                 //   Must be overriden for better results, by default
 110                 //   it just returns the Type name.
 111                 // </summary>
 112                 public override string ToString ()
 113                 {
 114                         return GetType ().FullName;
 115                 }
 116         }
 117 }